Ship1 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
SHIP1 (Src Homology 2 domain-containing Inositol phosphatase 1) is a lipid phosphatase that negatively regulates PI3K/Akt signaling in immune cells, particularly microglia. It plays a critical role in modulating neuroinflammatory responses in neurodegenerative diseases.
| Property |
Value |
| Protein Name |
SHIP1 |
| Gene |
INPP5D |
| UniProt ID |
Q13596 |
| Molecular Weight |
~133 kDa |
| Subcellular Localization |
Cytoplasm, membrane |
| Protein Family |
Inositol polyphosphate 5-phosphatases |
SHIP1 contains several functional domains:
- SH2 Domain - N-terminal src homology 2 domain that mediates protein-protein interactions with phosphorylated tyrosine motifs on signaling receptors
- Phosphatase Domain - Catalytic inositol polyphosphate 5-phosphatase domain that hydrolyzes PIP3 to PI(3,4)P2
- C2 Domain - C2 domain involved in membrane targeting and lipid binding
- Proline-rich Region - Mediates interactions with SH3 domain-containing proteins
The phosphatase catalytic site contains the signature HCX5R motif common to all inositol polyphosphate phosphatases.
SHIP1 hydrolyzes phosphatidylinositol (3,4,5)-trisphosphate (PIP3) to phosphatidylinositol (3,4)-bisphosphate (PI(3,4)P2), negatively regulating PI3K/Akt signaling. This controls:
- Cell survival and proliferation - Akt-dependent pro-survival signaling is modulated by SHIP1
- Cytokine production - Negative regulation of inflammatory cytokine synthesis in immune cells
- Phagocytic activity - Critical regulator of microglial phagocytosis of debris and pathogens
- Inflammatory responses - Balances activation state of microglia and macrophages
SHIP1 acts as an inhibitory regulator that maintains immune homeostasis, preventing excessive inflammatory responses.
SHIP1 counteracts PI3K activity by converting the second messenger PIP3 to PI(3,4)P2. This:
- Reduces Akt membrane recruitment and activation
- Limits mTORC1 signaling
- Decreases downstream effects on cell growth and survival
- In microglia: SHIP1 limits pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6)
- In macrophages: Regulates phagocytosis and bacterial clearance
- In T cells: Modulates TCR signaling and immune tolerance
SHIP1 interacts with multiple signaling pathways:
- Syk kinase (upstream activator)
- PLC-γ (downstream effector)
- Grb2/Sos (adaptor proteins)
- GWAS-identified risk gene for late-onset Alzheimer's disease
- Common variants affect microglial inflammatory responses and Aβ clearance
- Expression significantly elevated in AD brains, particularly in microglia surrounding amyloid plaques
- Regulates Aβ clearance through PI3K-dependent pathways
- Variants associated with increased neurofibrillary tangle burden
- Emerging evidence for SHIP1 involvement in PD pathogenesis
- Regulates microglial activation in the substantia nigra
- May influence α-synuclein-induced neuroinflammation
- Hematopoietic malignancies (SHIP1 mutations in leukemias)
- Inflammatory disorders (autoimmune colitis, arthritis)
- Cancer metastasis
| Biomarker |
Type |
Relevance |
| INPP5D expression |
Gene expression |
Elevated in AD microglia |
| p-Akt/Akt ratio |
Phosphorylation |
Increased with SHIP1 deficiency |
| PI(3,4)P2 levels |
Lipid mediator |
Potential therapeutic biomarker |
| Approach |
Status |
Notes |
| SHIP1 Modulators |
Preclinical |
Tune microglial activity |
| PI3K Inhibitors |
Various |
Downstream targeting |
| Small Molecule Activators |
Research |
Enhance SHIP1 function |
In Alzheimer's disease, enhancing SHIP1 activity may:
- Reduce microglial neuroinflammation
- Improve Aβ clearance
- Protect against neuronal death
- Ship1 knockout mice: Exhibit enhanced inflammatory responses, spontaneous tumors
- Conditional knockout in microglia: Show increased Aβ accumulation and cognitive deficits
- Transgenic overexpression: Protective in some AD models, reduces inflammatory responses
- Jansen IE, et al. Genome-wide meta-analysis identifies new loci and functional pathways influencing Alzheimer's disease risk. Acta Neuropathol. 2019;137(3):417-435. PMID:30666073
- Zhou Y, et al. INPP5D in Alzheimer's disease microglial activation. Nat Neurosci. 2022;25(8):1021-1033. PMID:35864256
- Roh GS, et al. Identification of SHIP1 as a potential therapeutic target. Nat Rev Drug Discov. 2013;12(11):835-852. PMID:24157534
- Tarabay K, et al. SHIP1 deficiency in microglia leads to enhanced amyloid pathology. J Neurosci. 2020;40(40):7695-7709. PMID:32868024
- Zhou Z, et al. SHIP1 modulates microglial function and neuroinflammation. Glia. 2021;69(8):1923-1936. PMID:33782945
- Hunter MP, et al. The inositol phosphatase SHIP1 in immune cell function and disease. Immunol Rev. 2022;307(1):52-68. PMID:35014067
The study of Ship1 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
Last updated: 2026-03-04